Snap-switch.



A. S. CUBITT.

SNAP SWITCH.

APPLICATION FILED MAR. 18, 1911.

1,01 1,754. Patented Dec.12,1911.

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. SNAP-SWITCH.

Specification or Letter: rum.

Application fled March 18, 1911. Serial No. 615,201. r

State of Massachusetts, have invented certain new and usefulImprovements in Snap- Switches, of which the following is aspecification.

The present invention relates to electric switches and more especiallyto reciprocab ing switches having a snap action, and has for its objectto provide an improved double snap switch consisting of few operativeparts, capable of -withstanding long and hard service and of low cost ofmanufacture. g The advantages of a switch operating with a snap act-ion,both in making and in breaking the circuit, have been long recognized bythose skilled in the art, but the mechanical means for practicallyaccomplishing such double snap action have been relatively complex andlacking in durability. Switches have heretofore been made in which a bowor buckling spring has been employed to produce the snap action, but, sofar as I am aware, none of the prior bow spring switches has gone intogeneral or practical use, although the mechanical simplicity, incidentto the use of the bow spring, was well recognized.

In carrying my invention into practice, I provide a suitable insulatingbase on which are mounted the stationary contacts and line terminals,and upon a suitable reciprocating actuator I mount a U-shaped contactoradapted to bridge and electrically connect the stationary contacts whenmoved into engagement therewith and having a bow or buckled springsprung in between its legs. The bow spring is connectedto thereciprocating actuator so as to be buckled from side to side of itsstraight line or dead center position, and on recoil the contactor willbe moved with a snap action from its operative to its extremeinoperative position or vice versa each time the actuator is operated.According to my invention the force applied to the actuator to break thecircuit operates to press the contactor into firmer engagement with thestationary contacts until the box spring has been moved to the oppositeside of its straight line or dead center position so that there is notime interval in which the contactor makes indifferent engagement withthe stationary contacts, and consequently all heating and fusing of theswitch members is avoided.

In the accompanying drawing formin a part of this specification, Figure1 is a p an view of one form of my switch with the contactor inretracted or open position; and

Fig. 2 is a similar view with the contactor 1n closed position.

The'base 1 is of porcelain or other insulating material made in the.form of a box with the bottom extended beyond the end walls 2 to formattaching feet 3. Stationary contacts 4 made L-shaped are secured to thebottom of the box at opposite sides thereof and each is provided with abinding screw 5 to receive the end of a line wire adapted to beintroduced through a hole 6 in the bottom;

The actuator 7 consists of a cylindrical insulating rod reduced at bothends to form shoulders 8 and supported for reciprocation in bearingsformed in the opposite end walls 2. The contactor 9 consists of a stripof spring metal preferably phosphor-bronze bent U -shaped with anaperture at the center ofthe bridge portion 10 of a size to permitthe-actuator 4 to pass freely theret-hrough and the ends of the legportions 11 are bent back to provide contact feet and adjacent theirends are provided apertures or recesses 12 for the pivotal reception ofthe ends of the bow spring 13. The spring 13 is a strip of fiat steelthreaded through an aperture 14 in the actuator 7 and of'a length tobow. out when sprung between the legs 11 of the contactor.

In order that the contactor 9 may be held against thestationary contacts4 under substantial pressure when in closed position, the actuator 7 ismade longitudinally expansible by a spring 15 engaging one end thereofand inclosed in a metal thimble 16 longitudinally movable in the bearingof the end wall 2 and spun out at its inner end after assembly of theparts.

When the parts of the switch are in the position shown in Fig. 1, bothsprings 13 and 15 are practically without tension. Movement of theactuator 7 to the right causes the spring 13 to straighten, forcing thelegs 11 of the contactor 9 apart until 13 passes the dead centerwhereupon the contactor snaps from full open to closed position, asshown in Fig. 2,with practically the full tension of spring 15 coactingto hold it Patented Dec. 12', 19111: 7

in engagement with the stationa contacts 4. Pressure exerted upon thethim le 16 will move the actuator 7 to the left causing the s ring 13 tostraighten and the legs 11 of the cont-actor to spread apart with theircontact ends wiping against the stationary contacts 4 until the spring13 passes the dead -center, whereupon the contactor snaps back to fullopen position. It will thus be seen that the contactor moves in bothdirections with a snap, so that destructive arcing cannot take place norcan the parts be set, that is with the bow spring 13 in straight lineposition and without tending to throw the contactor to extreme position.

I do not desire to restrict myself to the particular form or arrangementof parts herein shown and described, since it is apparent they may bechanged and modified without departing from my invention.

'What I claim as new and desire to secure by Letters Patent of theUnited States, is,

1. In an electric switch, the combination with a base having stationarycontacts, of a bridging contactor having flexible legs, a bow springengaging said legs, and an actuator.

2. In an electric switch, the combination with a base having stationarycontacts, of a bridging contactor having flexible legs, a bow springengaging said legs near their free ends, and an actuator for saidspring.

3. In an electric switch, the combination with a base having stationarycontacts, a bridging contactor having flexible legs, a bow springthrusting outwardly against the free ends of said legs, and an actuatorfor said spring.

4. In an electric switch, the combination of a base having stationarycontacts, a U- shaped contactor, a bow spring disposed between the freeends of said legs, and an actuator threaded through said contactor.

5. In an electric switch, the combination with a base and stationarycontacts, of a bridging contactor, and a longitudinally expansibleactuator for moving said contactor.

6. In an electric switch, the combination with a base and stationarycontacts, of a contactor, a bow spring for producing snap movement ofsaid contactor, and a longitudinally expansible actuator for saidspring.

-7. In an electric switch, the'combination with a base and stationarycontacts, of a U- shaped contactor-made in one piece, a bow springtending to spread the legs of the U- shaped contactor, a longitudinallyexpansible actuator threaded through the contactor and having anaperture through which the bow sprin is threaded.

In witness whereo I have hereunto set my hand this 15th day of March,1911.

ARCHIBALD S. CUBITT. Witnesses J. C. MUSGROVE, M. E. CANNING.

